Specific heat Terms Links

The term A C is linked to the molar specific heat capacities at constant pressure in the reference conditions of all the components of the reaction by the expression [4.6] ... 

For peroxide cross-linking, organic peroxides, such as dicumyl, di-t-butyl, and benzoyl peroxides, are used in amounts 1 to 3 phr (parts per hundred parts of rubber). Typical cure cycles are 5 to 10 min at temperatures 115 to 170°C (239 to 338°F), depending on the type of peroxide used. Each peroxide has a specific use. A postcure is recommended to complete the cross-linking reaction and to remove the residues from the decomposition of peroxide. This improves the long-term heat aging properties.62... 

More recent applications of the term (Bikiaris et ai, 1999 Daniila et al., 2002 Oliveira et al., 2002) appear to refer to naturally occurring and heat treated hematite-rich pigments producing a violet colour used in Roman, Byzantine and post-Byzantine art. Here, and perhaps due to the Latin name, caput mortuum is directly related to the purple pigments documented by the Roman authors Pliny (77 AD) and Vitruvius (first century BC), although the name was never used by either and in fact is unknown from other classical sources. However, it has been used synonymously with Pliny s and Vitruvius usta and ostrum although the link between these materials is, al best, tenuous. The pigments of these names described by Vitruvius refer specifically to T)rian purple and Pliny s usta refers to burnt cerussa (red lead qq.v.). 

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